


Parasitic

by Silex



Category: Original Work
Genre: Body Horror, F/M, Horror, Monsters, Pheromones, Rape/Non-con Elements, Underwater Sex, Xeno, unusual mermaid
Language: English
Status: Completed
Published: 2018-06-28
Updated: 2018-06-28
Packaged: 2019-05-30 00:31:05
Rating: Mature
Warnings: Major Character Death, Rape/Non-Con
Chapters: 1
Words: 4,991
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15085106
Author URL: https://archiveofourown.org/users/Silex/pseuds/Silex
Summary: A college graduate out sailing gets the surprise of a lifetime when he discovers mermaids are real. They don't resemble remotely resemble what most people think of when they think of mermaids though. Far from it.





	Parasitic

**Author's Note:**

  * For [OneEntireBee](https://archiveofourown.org/users/OneEntireBee/gifts).



> When this pairing was nominated for the exchange I made the comment that I'd be obligated to write it if someone requested it and that I hoped the person making the request knew what they were asking for. Funnily enough OneEntireBee made the comment in their request that they expected anyone willing to write this knew what they were getting into. Clearly this was a story that had to be written. I hope it's what you wanted OneEntireBee because it's such an interesting, terrifying idea that I couldn't resist. Also, I love your name so much! Which may also have been a factor in my wanting to write for you because I'm shallow that way.

After finishing university he’d had time to kill. His parents had made talk about how he should start looking for a job in his field. Yet they’d given him such a wonderful graduation gift, a sailboat, just like they’d promised, that he felt the need to enjoy it. So it was their fault really, that instead of looking into graduate school and begging professors to write him letters of recommendation, he was out cruising around a chain of seamounts, perfect for enjoying himself under the guise of productivity. He had majored in marine vertebrate biology after all, such a wonderfully specific field of study and appealing to so many of his interests.

Besides, it was a field where research took place on beaches and out in the open ocean rather than stuffy labs, like the ones where so many of his friends had ended up stuck, watching vials spin in centrifuges and endlessly pipetting samples from one container to another.

A boring waste of time if there ever was one, and all to someday maybe be the third person down in the list of authors on an article about the effects of organic pesticides on the weight of honeybee gonads. That wasn’t what he wanted, not at all.

And unlike so many of his former fellow students, he wasn’t weighed down by debt, thanks to his parents paying his way through college. A legacy scholarship was what the school had called, but it was really because his father and grandfather had gone there and made a sizable donation towards the new library in years past.

He’d chosen the school not because of the free ride, though it had been a factor, but because of its proximity to the beach, several clubs and assorted other tourist hotspots. When he wasn’t in class he’d spend his time wandering around, playing tourist and taking pictures. Photography had been his hobby for the longest time, ever since his parents had gotten him a camera for his birthday.

For the first few semesters he’d majored in ‘undecided’ until his parents demanded that he start focusing, so he had, on the classes that kept him away from the campus as much as possible and out on the water. In the process he discovered that he had a genuine interest in marine biology. Fish were fascinating, utterly alien and hidden out of sight just below the water. From the first time he’d seen the absolutely hideous dentition of a blackfish he’d been hooked so to speak. Never had he imagined that something so strange could at any time, be just a few feet away.

It was exciting and a way to call fishing and boating and enjoying himself on the beach productive.

And the seamount he’d spent the past week cruising around was in an area of upwelling, carrying cold, nutrient rich water from the depths to the surface, providing host to all manner of strange creatures. When his parents called him over the satellite phone the boat was equipped with he told them the full truth, that he was hoping to discover a new species.

Because he was sure that the shadowy thing he’d seen wasn’t any known species. The first time he’d caught sight of it he’d assumed that it was a bit of seaweed pulled loose from the bottom, or maybe drifting trash.

Then he’d realized that it was moving against the current.

He’d tried to get closer, but as he drew near the thing vanished into the depths.

The next day it returned, closer than before, enough so that he was able to snap a few pictures and get an estimate of its length. By his figuring it was about two meters from tip to tail, assuming that it had a tail, making it large enough to be either a dolphin, a marlin, a sailfish, a tuna or any number of other forms of aquatic life found in the area. It wasn’t though.

He’d looked at the pictures he’d taken, poured over them really, and the body plan didn’t fit any of those creatures, nor did its behavior.

With its blunt head it could have been a Risso’s dolphin, but he knew it wasn’t. For one, he’d never seen it surface and its behavior, the tendency to just float there, didn’t match.

For the same reason he was able to eliminate most types of large fish commonly found in the area. All of them were too active, and this thing, whatever it was, was far too passive. It moved to stay in place, parallel to his boat, but that was it.

Then there was its body plan, slender towards the head end, with a large midsection and blunt tail, or at least he assumed that the projection at the back end was a tail. He could have easily been mistaken and the whole area he had taken to thinking of as the thing’s body was actually its tail.

Strange and illusive as it was, he could understand how people came to believe in sea serpents, because he was sure that he was to some degree, imagining things when he looked at it. He thought it had two long projections near the front of its body, fanning out at the ends, but those could have just as easily been tricks of the light.

What he had was a basic silhouette and glimpses from a distance, nothing more, at least not in terms of what the thing looked like.

In terms of behavior he had more to work with. Though he’d first seen it during the late afternoon it was more active in the early morning and near sunset. A few times he’d seen flashes of slight at night, luminescent organisms disturbed by the passage of something large, but it was too dark to tell what. It never surfaced, staying, by his estimates, a foot below the water at all times.

And it was showing up with increasing frequency and staying longer each time.

That might have been because of the adjustments he’d made to his routine though, getting up just before sunrise to watch for it and keeping an eye on where he expected it to be as the sun dropped lower in the sky. Maybe he was seeing it more because he knew what he was looking for. If only he could get a closer look.

Unfortunately it never approached close enough for him to get a good look at it and any time he tried to approach it would retreat. The first few times it submerged and vanished, but lately it had simply maintained distance.

If the thing proved to be a sea turtle caught in a net he was going to be sorely disappointed, but he reminded himself, that was always a possibility.

He desperately wanted it to be a new species though, something that would make him famous, not for the sake of being famous, but because it would be a satisfying resolution to the mystery of what the thing was, an adventure where he got to make the end himself.

Until then he contented himself to watch and wait and take pictures.

Watching lights flash in the water after dark he became more and more convinced that the creature was circling his boat. There was a pattern to it, ever tightening spirals, closer and closer, and the size of the disturbance matched the size of the creature.

His first guess at its size had been wrong, it was closer to three meters long, just right to be a dolphin, but its movements were too slow and measured.

So what he could assume was that it was a large, nocturnal predator, which did nothing to narrow down what it might have been. Eventually he’d get lucky though, it was just a matter of being patient.

Later that night his patience finally paid off, though he didn’t realize it at first.

He didn’t know what woke him up, just that one moment he was asleep, the next he was wide awake.

Lying in bed he listened, relaxing slightly when he didn’t hear any alarms. That was always his biggest fear when he let the boat drift at night, that it would start taking on water for no reason, or a storm would roll in. Storms in the open water came without much warning and he always listened carefully for thunder.

So far none of them had been too bad, mostly just distant thunder and the wind picking up. Sound carried more than you’d expect in the open water.

But that wasn’t it either, the boat rocked gently in the water, no wind or rain to be heard.

Maybe something had fallen. That was always a problem if he wasn’t careful and failed to secure some small, unimportant thing before turning in for the night.

He’d find it in the morning, or whenever, not that it mattered.

Adjusting his pillow he rolled over and tried to get back to sleep.

Something didn’t feel right, though he couldn’t put his finger on what it was.

He listened to all the normal night sounds.

Something shifted. A door creaked open and then banged shut.

That was it then, he’d forgotten to close a door and it being bounced off the wall by the boat’s movement had been what had woken him up.

Mystery solved. It was closed now and he could go back to sleep.

Another creek.

Had the latch broke?

No.

This was closer.

Two doors that he’d forgotten to close then.

That wasn’t too hard to believe.

It wouldn’t been the first time he’d left one open or only thought he’d closed it.

Except now that he was listening, really listening, he could hear something moving. Not some fallen object rolling or sliding back and forth, but something large and heavy moving with a purpose.

He’d heard absolutely hilarious accounts of sea lions jumping onto boats, but this wasn’t the hopping shuffle of one of them. Besides, they wouldn’t be able to open doors.

He could hear it moving now, dragging itself across the floor and letting out deep, gasping breaths. Definitely not a sea lion.

There was nothing out there that he could think of that would be able to harm him if he was careful, but at the same time there was nothing that he could think of that would sound or behave like the thing outside.

He could hear it on the other side of the door, sniffing loudly, heavy, wet inhalations followed by a soft, raspy wheeze.

The knob turned and the door swung open.

Whatever it was remained just outside the room, sniffing and wheezing excitedly. There wasn’t enough light below decks to see much, but he got the impression of something large and low to the ground. Light from some piece of electronic equipment out in the hall glinted off its slick hide.

No, the darkness was playing tricks on his eyes. The little blue light wasn’t behind the thing, it was in front of it, flicking up and down.

Animals didn’t carry electronics with them. Immediately he reassessed what he was seeing, not some unknown, formless bulk creeping in the darkness, but a person, hunched low to the ground, cellphone held high to light their way.

“Who’s there?” He demanded as he reached for his flashlight.

Pirates weren’t a thing, not out where he was at least, and if they were members of some agency they would have announced themselves before boarding.

More loud sniffing.

Maybe they were injured, a fellow boater whose vessel had capsized.

But he hadn’t heard any distress calls since he’d been out here.

He turned on the light.

Even looking straight at the thing it took a long time for what he was seeing to register, and even then only bits and pieces at a time.

The bulk of its body was a sort of blotchy gray-brown, or at least its torso was, because it had a distinct torso. It was laying on the ground, long, thin arms holding its front half up while its back half, hunched and irregularly shaped, lay behind it, a limbless black mass.

No, not limbless, the lumps and projections were fins. Two rounded pectoral fins where the torso and lower half met and set very far back a small, ragged dorsal fin.

The fins were very recognizable, but they didn’t make sense.

It had arms, arms and spindly, webbed fingers.

A lean, human looking torso, ribs plainly visible under wrinkled flesh.

The face though.

There were eyes, perfectly round and a sightless white in a dark, skeletal face.

The thing inhaled again, esca flicking up and down, light from the luminescent lure at the tip shining on its teeth.

It had a lot of teeth.

More than could fit in its mouth and it had a very large mouth.

No nose though, at least none that he could see past the teeth, long teeth no two the same length.

Gills on its neck and down its chest and where the torso met the lower body opened and it wheezed, pushed itself up a little higher and looked at him.

He had to be dreaming.

There was no way the thing he was looking at could be real.

Its gills closed and it heaved itself forward, into the room.

It was a mermaid. Not some fairytale creature, but a Fiji Mermaid come to life.

He lay as still as he could, wondering when fear would wake him.

The thing, the mermaid, continued to drag itself towards him.

For a dream it was remarkably vivid, little details like the glowing lure at the end of its esca, the positioning of its gills, even little bumps of scar tissue along its fin rays. The thing even had a smell to it, briny yet somehow, disturbingly, female.

When it reached the bed it paused for a moment, looked at him and tilted its head to the side.

This let him get a good look at its face, roughly human in shape, but expressionless and devoid of any humanity. There was a certain intelligence in its small, blank eyes, but nothing that could be related to.

Slit nostrils flared as it inhaled, its mouth opening wider. A hand reached up, cold, slimy fingers brushed against his face, ran through his hair.

That seemed to fascinate the mermaid, understandable as it was completely hairless, with small, spiny fin rays clustered more densely around its esca and sticking up randomly elsewhere on its otherwise smooth scalp.

Mouth opening and closing soundlessly, it placed both hands on the bed.

He could feel the bed shift from its weight, the covers slide away.

Impossibly vivid.

It pulled the covers the rest of the way off of him, looked at his body.

He could actually feel its esca flitting against bare skin.

Tap – tap – tap across his chest, his stomach, and lower, growing increasingly rapid the whole time.

Somehow, despite his terror, despite its cold touch, he was rock hard, which seemed to be of particular interest to it.

“Wh-what do you want?”

He nearly laughed at himself, talking to a nightmare, but he wasn’t waking up and felt the need to do something, anything.

More movements of its esca, back and forth this time, right in front of his face, the light leaving afterimages dancing before his eyes.

There was a pattern to it, a design traced out in the air punctuated by the occasional tap against his face

The mermaid was trying to communicate.

“I don’t understand.”

Dream or not, there was no harm in going along with things and he was becoming more certain by the moment that it wasn’t a dream. The mermaid had been the shape in the water, watching him. It had chosen tonight to approach him. He’d discovered a new species and it was beyond anything that he could have imagined, which was part of what made him think that it might not be a dream. He never would have imagined a mermaid so hideous and alien that it couldn’t communicate with him.

Her esca came too close to his eyes and he winced away, “Whatever you want I don’t know. I’m sorry.”

The taping stopped, her esca flicked back and she stared at him in an uncomfortably animal way. She was intelligent, her attempt at communicating made that clear, but it wasn’t a human intelligence.

Mouth opening in a harsh wheeze of effort she pulled herself onto the bed, her weight making it creak.

She was larger than him, much larger. It was something he hadn’t appreciated until she was practically laying on top of him.

A few more movements and she _was_ laying on top on him, her body cold and smooth. Even her lower, piscine half, was scaleless. It made as much sense as any of it he supposed. What she resembled more than anything was an anglerfish and as far as he could recall most species of anglerfish lacked scales.

She wiggled and shifted her weight on top of him, her slimy bulk putting enough pressure on his legs to hold him in place.

“Hey! Careful,” he reached out and put a hand on her shoulder.

Instantly her whole demeanor changed, curiosity replaced by enthusiasm. Instead of shifting her weight from side to side she began to move back and forth until it happened.

He hadn’t realized that his inexplicable erection remained until her moving caused him to slide inside her.

“What the?”

In response she pressed down harder against him as though trying to ride him, not that she was built for it. Her movements were slow and awkward, the inside of her as cold as her skin and above all he wanted nothing of the sort.

She hissed, the slime of her belly cold against his stomach and legs. Her opening, he couldn’t think of it in any feminine terms, was muscular and slick, tight at the base of his cock, but otherwise unpleasantly loose, likely meant for anatomy very different than his own.

“Stop it!”

He tried to pull away, but she fell on top of him, pinning him to the bed with her weight.

Heavy as she was, she wasn’t strong and if he couldn’t push her off of him he could try rolling her.

Beneath her he shifted his weight, pushing deeper inside her in the process, earning a soft sigh in response, then he pushed to the side.

Her arms wrapped around his shoulders and they rolled off the bed together.

Landing on top of her should have given him the advantage, but she kept her arms around him in a near suffocating embrace. It was the smell of her, it hit him like a wall, sour and inhuman, but with an almost cloying undertone. Somewhere, deep in some primitive, animal, corner of his brain it registered as female and somehow desirable while the rational part of his mind screamed in panic.

She ground against him and reflexively, involuntarily, he thrust into her.

Her arms loosened and she pushed back to look at him, mouth falling open in what might have been surprise.

He tried to take advantage of the situation and push her arms off of him or roll off of her, he wasn’t sure which and would settle for either, anything to get away from her. Further helping his efforts, she chose that moment to try to turn slightly, loosening her hold on him.

Strands of her slime stuck to his stomach and chest in long, viscous strings as she pulled back. It was getting thicker, drying out in the air, gluing the two of them together. Between the slime and the muscles of her slit she held him against her, inside of her.

Her gills flared and she wheezed, fins and small, frayed tail slapping against the floor as she tried to turn around

“Stop it! Let me go!”

He thrashed and tried to get his legs to one side of her or the other so that he could stand.

In response she grabbed one of his legs, held it awkwardly at her side where her upper and lower halves met, then rolled over onto that side, pinning that leg beneath her.

It wasn’t long before her weight began to cut off circulation to that limb, except, he realized, it wasn’t just her weight.

His stomach and groin tingled where he was in skin to skin contact with her, his hands as well, from trying to push her away.

Was her slime toxic? He tried to remember what he could about anglerfish, since that was what she resembled, but he couldn’t recall if there were any that were poisonous. Then again she was different enough from anything that he had studied that what he knew meant little.

Hissing with effort she rolled back onto her back again, something about the movement causing him to thrust into her again, prompting a shorter, sharper hiss and gasp another of surprise, or maybe amusement.

Free of her weight, he tried to move his leg and found it completely unresponsive. More than that, it seemed stuck to her side.

When she tried to grab his other leg he pulled away and grabbed her hands.

In response she simply rolled over, this time pinning his leg at a far more awkward angle.

Something in his foot popped and he cried out in pain.

The pain left him lightheaded and he let go of her hands as unconsciousness threatened to overtake him.

A new jolt of pain brought his senses into sharp focus for an instant as she moved, flashes of white shooting across the gray haze at the edges of his vision.

Each movement brought with it a fresh stab of pain, pushing him further and further towards passing out.

By the time he regained his senses enough to be aware of anything other than pain from his broken foot she’d managed to roll onto her belly and dragged herself outside, bringing him along for the ride.

The pain was fading, replaced by a tingling numbness.

Everywhere he was in contact with her was like that, except for his cock, there it felt like his sensitivity had been heightened, every move she made, every twitch of her muscles was magnified in the most pleasurable way possible. Unable to help himself he thrust into her, feeling her muscles clench against him so hard it was almost painful, keeping him locked in her.

“What are you doing?”

As though the answer wasn’t obvious. She wanted to get back in the water and unless he could get away he’d be dragged along with her.

His numb and immobile legs meant that his attempts to push away blended with his thrusting until the two were one and the same.

This wasn’t working and she already had her hands on the side of the boat.

If he didn’t pull free soon she’d be over the side and then –

He didn’t want to think about what would happen then.

Sitting up against her to gain leverage, in the process pressing his chest against her, he reached down and tried to grab at his leg.

Touching it was like touching a piece of wood, he could feel it there with his hands, covered in slime, but he couldn’t feel his fingers.

Nor could he feel the space between his leg and her side. Her slime had glued him so thoroughly in place that he couldn’t even force his fingers into the gap.

Because there was no gap.

Further down, where his foot rested against her back, should have rested against her back, his hands found a lump toeless and far smaller than it should have been.

Her slime was corrosive, melting him into her. That was why the pain from his injury was fading, because his foot itself was dissolving.

She reached up, grabbed the side of the boat and made a few testing motions before she began to pull herself up over the side.

He tried to push away, force her back from the water, but he had less range of movement than he had before.

Ignoring his efforts, she leaned forward, trapping him between her and the side of the boat.

Immediately, a wave of pleasure washed over him and he bucked beneath her, uncertain if he was fighting her or riding the wave of sensation. It grew and grew, mounting within him reaching a crescendo as the single most powerful orgasm he’d ever experienced.

Apparently not every part of him in contact with her had gone numb or melted away. His cock seemed to be working just fine.

Above him she rasped and wheezed, pressing him down harder and harder, her blunt tail lashing violently back and forth. Her movements, he realized, when the haze of pleasure began to pass, were in time with the lingering tremors running through him. She’d climaxed at the same time as him.

Her whole body shook violently and he gasped.

That reflexive action saved him, for the very next instant she fell over the side of the boat and into the water.

It was cold, enough so that the urge to exhale was strong, but he knew that if he did he’d be as good as dead, though he couldn’t help wondering if drowning would be preferable to what was happening to him.

Then she began to twist in the water, bouncing him against her and all thought vanished for a while as he could feel yet another orgasm building.

This time the feeling was distant, leaving him to wonder how much more of him had faded away. Yet he could still feel her muscles tensing around him, even as the numbness that had started with his legs spread up his stomach to his chest.

Below the water it was silent save for the blood pounding in his ears and the frantic beating of his heart, an internal cacophony that made it nearly impossible to concentrate.

Her hands found his back, pressing him against her, forcing the air from his lungs in a stream of bubbles that shone an eerie blue in the light from her esca.

He watched them scatter when she rolled through them, and then vanish from sight as they fell away into the darkness above.

It wouldn’t be long before lack of oxygen caused him to black out, sparing him from whatever came next.

Another orgasm, strange and somehow wrong. Rather than bringing a sense of tiredness and satisfaction it left his cock aching and him wanting more. Though he was sure he’d come at least twice already he needed to come so badly it hurt.

When he tried to pull away to gain leverage to thrust he discovered that he was unable to, but he needed to. Not to escape, but to satisfy the growing need that his most recent orgasm hadn’t.

He couldn’t move, couldn’t thrust.

Her hands found his arms, guided them around her and he held on, trying desperately to plunge deeper into her.

She put her hands on his back, moved him and pressed him into the right place as his own muscles had degraded too far for that.

The only light to be seen was that of her esca and its faint illumination brought a softness to her inhuman features, she was still horrifying and hideous, but there was something compelling about her.

Something that was indescribably arousing.

He came explosively, staring at her skeletal face and lipless, fanged mouth. White eyes, reflecting blue light, were fixed on him, lidless and unblinking.

She threw her head back when he came, her mouth opening wide in a soundless cry of pleasure.

Her hands, they felt so much larger now, drifted from his back, so that she could run her long, clawed fingers through his hair, caressing him as though in affection.

His ears popped.

Until that moment he hadn’t realized that they were going steadily deeper.

His mouth was open, he could taste the salt, feel the sting of it in his nose, that and the tingling numbness spreading up his neck.

What he couldn’t feel was his lungs burning for air, the ache in his chest from holding his breath for so long.

Yet he wasn’t dizzy either, his thoughts were remarkably clear given the situation.

He waited, but no need to breath came.

Morbid curiosity got the better of him and he tried to inhale only to discover that he was unable to.

Panic returned, but the sound of his pulse in his ears remained steady, relaxed and listening to it he began to feel calm.

He couldn’t breathe, couldn’t feel his heart beating in his chest, but he could feel a heartbeat, its rhythm slow and soothing.

It was her heartbeat.

The numbness was spreading up his back so that when her fingers left his hair to trail along his spine the point where she was touching him and touching herself was blurred.

Lower down it seemed that nerves were entwined, he could feel sensations where he was sure there was nothing left of him. Then her fingers caressed the base of his cock, fondled his balls, which were somehow still there and he tensed.

She tensed as well.

They’d both felt that.

Another orgasm was building, not his, but hers.

He could feel it though, distant, relayed through her nerve endings to his.

Fear was fading, washed away by her pleasure.

He could feel it like it was his own.

She spun in the water and he could feel the movements of her muscles, feel her stroking him, herself.

Back and forth.

Him.

Her.

Him, her.

She came.

He came.

Not at the exact moment, but a chain reaction.

It felt good, so good.

No fear.

Just pleasure.

Her pleasure.

Everything else was fading, but pleasure remained.

He lost himself to it.

Drowned in it.


End file.
